The present invention relates to a device and method for waking up a microcontroller unit (MCU) operating in a sleep mode.
Recently, a high power secondary battery using a non-aqueous electrolyte having a high energy density has been developed. To be used for devices that require strong power for driving motors such as electric vehicles, a plurality of high-output secondary batteries are connected in series to constitute a large-capacity secondary battery.
As described above, one large-capacity secondary battery (hereinafter referred to as “battery”) is usually composed of a plurality of batteries connected in series. Particularly, in the case of a battery for a hybrid electric vehicle (HEV), as several to dozens of batteries perform charging and discharging alternately, there is a need to control the battery so as to maintain an appropriate operating state while controlling such charging and discharging.
To this end, a battery management system (BMS) for monitoring the state of the battery as a whole is provided. The BMS monitors the battery voltage, current, temperature, etc. to estimate a state of charge (SOC) of the battery by calculation and controls the battery so that the fuel consumption efficiency of the vehicle becomes the best.
Meanwhile, when the SOC of the battery drops below a predetermined value, the MCU of the BMS also operates in the sleep mode in order to protect the battery and to prevent discharging and reduce battery consumption.
Since the MCU of the BMS operating in the sleep mode does not operate until the wake-up signal is applied, in order to control charging/discharging, conventionally, a user has to wake it up.
In this way, it is troublesome for a user to wake up the MCU of the BMS in the sleep mode directly.
As a solution to this problem, there is a technique of waking up the sleep mode BMS as an external power source when the external power source is applied.
In relation to the technique of waking up the sleep mode BMS in this manner, if an external power source is connected, it will continue to wake up the BMS so that even if the SOC of the battery becomes a predetermined value or less, the BMS may not return to the sleep mode again. Thus, there is a problem that the battery is over-discharged.
Therefore, when an external power source is inputted, the present invention generates the MCU of the BMS, which is in the sleep mode only once, in order to wake up the MCU of the BMS. Even if an external power source is connected after the MCU of the BMS wakes up, when the SOC of the battery is insufficient, a device and method for the MCU of the BMS to operate in the sleep mode again are proposed.